DE2217494A1 - Alkoxypropionitriles prodn - from acrylonitrile and alcohols using catalyst - Google Patents

Abstract

Catalyst produced by reacting methanolamine with ethylene oxide used in the prodn. of methoxypropionitrile from acrylonitrile and methanol according to the Parent patent was found equally effective with respect to reactions of acrylonitrile with mono- or polyhydric alcohols contg. >=2C atoms. The resulting title cpds can be used as inters. in the prodn. of acid amides, amines or diamines, isocyanates, etc. The catalyst is relatively inexpensive.

Description

Process for the preparation of alkoxypropionitriles. Addition to patent . ... ... (patent application P 21 21 325.2).

Subject of the main patent. ... ... (patent application P 21 21 325.2) is a process for the production of methoxypropionitrile from acrylonitrile and methanol with the help of a special quaternary ammonium base as a catalyst.

The invention relates to a further embodiment of the method according to the main patent.

It was found that the process according to the main patent. ... ... (patent application P 21 21 325.2) for the production of methoxypropionitrile by Conversion of herylnitrile and methanol in the presence of a basic catalyst, where the basic catalyst is a reaction product of triethanolamine with ethyl lenoxid is used, advantageous to the implementation of acrylonitrile with a monohydric or polyhydric alcohol with at least 2 carbon atoms can be used, the corresponding mono- or polyfunctional alkoxypropionitriles in high yield are formed. In the case of 1,2-diols, however, there is usually only one hydroxyl group substituted or undesired side reactions occur; this appearance has been observed before and apparently cannot be attributed to the catalyst to be influenced.

The possibility that the catalyst according to the invention (tetra ethanol ammonium hydroxide is suspected as the active substance in the catalyst) also the implementation of higher Alcohols Catalyzed with acrylonitrile with good success was not to be expected without further ado: other quaternary bases such as trimethylbenzylammonium hydroxide show very different behavior here.

An advantage of the invention can thus be seen in the knowledge that the catalyst according to the main patent can be used very generally with advantage, even if it is not superior to a known catalyst in individual cases is. Another significant advantage of the catalyst according to the invention over known quaternary bases is its easy accessibility. It is well known that Production of quaternary ammonium bases, e.g. by pricing from the ammonium halides by means of silver oxide, very cumbersome, while reaction products from triethanolamine and ethylene oxide can be easily obtained on an industrial scale.

The catalyst allows the conversion of acrylonitrile with one or more dihydric alcohols with e.g. 2 to 20 carbon atoms to alkoxypropionitriles and alkylene-bis-oxypropionitriles, which in turn are intermediates, e.g. for acid amides, amines, isocyanates and others. The diamines produced from the alkylene-bis-oxypropionitriles are particularly good Epoxy resin hardener.

The alcohols mentioned - provided they have a sufficiently large chain length, they can also be trivalent or polyvalent - can have substituents below the reaction conditions behave indifferently, for example fluorine atoms, tertiary amino groups, nitro groups, nitrile groups, sulfonic acid or carboxylic acid groups in the salt form, etc. In particular, for example: ethanol, n-propanol, isopropanol, stearyl alcohol, tridecyl alcohol, 1,3-propanediol, 1,4-butanediol, 1,5-hexanediol, Trimethylolpropane, triethanolamine, 1-nitro-hexanol- (6) and especially 2-ethylhexanol. The reactants are used in approximately equivalent amounts and the reaction carried out at normal temperatures, e.g. at 20 to 2000C. One can use a solvent use or not; in some cases can the reacting Alcohol serve as a solvent in excess. In principle, the acrylonitrile is also used for this suitable, although this method should not have any advantage in general.

When the reaction has ended, the catalyst becomes particularly advantageous separated by the fact that one forms its phosphoric acid salt, which crystallizes in well orm can be easily separated.

Example 1 1,300 kg of 2-ethylhexanol and 30 kg of a reaction product of equimolar amounts of triethanolamine and ethylene oxide mixed. At a temperature of 50 to 550C one leaves within 3 hours 556 kg of acrylonitrile, which is stabilized with 0.2% hydroquinone, run in and stir an hour after. Then 39 kg of 84% aqueous phosphoric acid are added and stir for another hour. The precipitated salt is filtered off.

1,828 kg of 2-ethylhexyl-oxypropionitrile are obtained (yield 99% of the Theory), its purity of 98.8% practically only due to the purity of the starting materials seems limited.

Example 2 As described above, 1,800 g (= 20 mol) Butanediol (1.4) with 2230 g (= 2.0 mol) of acrylonitrile in the presence of 36 g of one Catalyst around, by mixing equimolar amounts of triethanolamine and ethylene oxide had been received. The amount of phosphorus ERre added to separate the catalyst is 48 g (84% acid at 100%). An yield of 93.5% dinitrile is obtained; 1.3 moles (i.e. 6.5 of theory) of the butanediol are only in the monoethoxynitrile has been converted. Correspondingly, additional to the original excess from 5 mole percent acrylonitrile a certain additional amount of acrylonitrile, in total 3.2 moles found.

The amount of solid, filterable by-products is less than 0.1.

Claims (1)

Claim Another embodiment of the process for the production of methoxypropionitrile by reacting acrylonitrile and methanol in the presence of a basic catalyst according to patent. ... ... (Patent application P 21 21 325.2), where a basic catalyst Reaction product of triethanolamine is used with ethylene oxide, characterized in that that it is based on the reaction of acrylonitrile with a monohydric or polyhydric alcohol with at least 2 carbon atoms.